Friction type fuse device



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Filed 001'.. ll, 1954 J. G. VILLEPIGUE ET AL FRICTION TYPE FUSE DEVICE Jan. 20, 1959 ERICTION TYPE FUSE DEVICE Julius G. Villepigue, Inglewood, and Edgar ySchmued, Los Angeles, Calif., assignors to Northrop Aircraft, Inc., Hawthorne,

Application October 11, 1954, Serial No. 461,350 7 Claims. (Cl. 102-49) Our invention relates to fuses, and more particularly t a novel fuse for use in spin-stabilized rockets and the li e.

The term rocket as used herein is intended to include both guided and unguided solid fuel type reaction driven missiles.

To reduce the tendency of a missile to tumble in tiight subsequent to launching, and improve the stability thereof over the ight trajectory, a means and method of spin-launching, and spin-stabilizing a rocket during ight, is described, shown, and claimed in co-pending U. S. Patent applications: Serial No. 425,594, tiled April 26, 1954, by Edgar Schmued et al., and Serial No. 425,595, filed April 26, 1954, by Edgar Schmued, wherein initial stabilizing spin is imparted to a rocket in a launching bed or tube during launching thereof so that the rocket will leave the launcher in a spinning condition to thereby provide gyroscopic stabilization of the longitu dinal axis of the rocket upon entering the initial acceleration phase of its flight trajectory.

One object of our invention is to provide a simple yet reliable fuse for use in spin-stabilized rockets.

Another object of our invention is to provide a simple fuse for spin-stabilized rockets which does not re- Aquire power circuits or controls for actuation thereof.

A further object of our invention is to provide a fuse lfor spin-stabilized rockets which is independent of ex- .ternal or internal power circuits; the fuse being actuated .solely by physical forces produced in the rocket itself :during launching and flight thereof.

Still another object of the fuse of our invention is to provide a simple, economical fuse for spin-stabilized rock- Iets, which fuse cannot be actuated except by calculated forces produced in the rocket before and after the initial launching phase thereof, thereby providing a maximum of safety in handling.

Other objects and advantages inherent in the fuse of our invention will be readily perceived-as the specification continues.

Briefly, the fuse of our invention comprises a fuse body mounted in a spin-stabilized rocket between the warhead, or explosive charge, and the combustion chamber which contains a propellant charge. vAdjacent the propellant charge a primer charge, forming part of the fuse, is positioned in line with a spring-actuated firing pin which is releasable by centrifugal force only. Adjacent the warhead, a detonator is positioned; the detonator being extremely sensitive to heat generated by a pair of friction elements which are actuated by deceleration of the spin stabilized rocket upon reaching a target, or in case of a miss, upon 'burn-out of the rocket propellant charge.

Our invention will be more clearly understood by referring to the drawings wherein:

Fig. l is a side elevation view of a rocket in section, showing a preferred embodiment of the fuse of our invention mounted therein.

Figure 2 is a sectional view taken on line 2-2 of Figure l.

Figure 3 is an enlarged longitudinal section view of the fuse of the present invention.'

Calif., a corporation of Californial 2,369,464; Patented Jan. 20, 1959 Figure 4 is an exploded view, in perspective, of the fuse of Figure 3.

Referring to Figure 1, a rocket 10 is shown in launching position in a launching tube 11. `Rocket 10 comprises a warhead 12 containing an explosive. charge 14, a charge of solid propellant 15 within a combustion chamber 16, and an exhaust nozzle 17 through which the products of combustion, or gases, resulting from ignition and burning of the propellant, escape to provide the necessary thrust to propel the rocket 10 forward.

`At the rearward or exhaust end 19 of launching tube 11 and adjacent the exhaust exit of rocket exhaust nozzle 17, a spinmotor or spinner 20 is provided, being mounted to rotate about the longitudinal axis of launching tube 11. As shown herein, the spinner 2t) is preferably housed in a heavier gage tube or casing 21 which is coupled to the end of launching tube 11 by means of coupling threads 22 for example, although in some cases the launching tube could be satisfactorily adapted to house the spinner.

A spinner sleeve 24 is rotatably mounted in spinner casing 21, the rearward end 25 of the sleeve 24 being coterminous with the exhaust end of the casing 21, or launching tube 11 as the case may be. The sleeve 24 is preferably internally coned or flared at either end, and the outer diameter of the sleeve is reduced between each end to dene a peripheral recess 26 in which a torsion spring 27 is retained.

One end 29 of spring 27 abuts, or is connected to, a

lug 30 provided on the inner wall of casing 21, the other end 31 of spring 27 abutting, or being connected withv another lug 32 provided on spinner sleeve 24 adjacent the exhaust end thereof.

Opposite the spinner sleeve recess 26, the diameter of the internal surface or wall of casing 21 is increased to permit the spinner spring 27 to expand laterally when unwound.

An internal circumferential groove 34 is provided in casing 21 adjacent to the exhaust end thereof and is counter to a circumferential groove 35 provided around the exhaust end of spinner sleeve 24, the grooves 34 and 35 providing inner and outer races for ball bearings 36 upon which the spinner sleeve 24 is rotatably mounted.

A driving key 37 provided on the end of spinner sleeve 24, adjacent the exhaust nozzle 17 of rocket 10, is engaged in a driving key slot 39 provided on the exhaust end of rocket 1t) by which means rocket 10 is spun by spinner 2t).

A somewhat volute camming groove 40 is provided around the exterior periphery of rocket exhaust nozzle 17 gradually running from a maximum depth indicated A release pin 41 which is extended through aligned i bones43 in a leaf spring 42, the launching tube 11 and spinner casing Z1, is positioned in camming groove 40; being mounted on leaf spring 42 which is in turn fastened on the exterior surface of casing 21.

When the spinner spring 27 is wound ready to spin the rocket 10, release pin 41 assumes the position shown in Figure 2 and prevents forward movement of rocket 12 in launching tube 11, spinner spring 27 being retained in wound condition by means of a stop pin 44 which extends through a pair of aligned bores 4S through leaf spring 42, spinner casing 21, and into an indent or recess bore 46 in spinner sleeve 24.

Winding keys 47 are provided, in any convenient n1anner, in the exhaust exit of spinner sleeve 24 so that a suitable winding tool or crank (not shown) can be engaged therein to wind the spinner. spring 27 to vfull wound position. f

The spinner 20, casing 21, and concomitant rocket nozzle structure, is not per se -a claimable part of the present invention, butrforms one embodiment of the invention described, sho-wn, and claimed in U. S. Patent application Serial No. 425,595; supra.

Thus, when spinner spring 27 is released togunwind,

by pulling stop pin`44 out off'detent bore 4,6,.-the rocket 'is sp'un about the longitudinal 'axis thereof, and at the same instantof spinning, thefrocketpropellant charge is ignited, by means of thecentrifugal force produced =byy spinning, to launch the rocket 10 in a spinning condition. The spin simultaneously cams release pin 41 out of camming groove 40 toreleaseethe'rocket 10 fory having an elongatedtubular boss 54 in the center thereof.

Extending from within the boss 54, and into the rocket combustion chamber 16 is a tubular frangible cartridge 55V filled with a suitable primer for igniting the propellant charge 15. A percussion cap 56 such as a fulminate type cap, for example, is coaxially positioned on the end of the primer cartridge 55 which' is fastenedvto the `end of the boss 54. Inside the boss 54,one end of a sleeve V57 is extended, -being press litted thereinto, theother end 'of the sleeve 57 terminating with a closed end 59 having a coaxial pintle or pivotal bearing ,60 thereon.

At a point between the ends of sleeve 57 -a number ofslots y61V are cut through the sleeve wall to receive therethrough'arcuate retaining portions v62 of a segmented centrifugal release collar 64. vA'fvcollared firing pin 65 is slidably mounted in sleeve 57Vand coaxially positioned 'th respect to percussion cap 56 ofprimer cartridge 55. Firing pin 65Uis' urged-toward percussionV cap 56v by a compression spring 66 mounted between the closed end'or' ring pin sleeve 57 and one face of collar 69 of tiring pin 65. The opposite face of firing pin collarV 69 abuts'the arcuate retainer portions 62 of'centrifugal release collar 64 which are extended through sleeve slots 61. The segmentedfportions of Vcentrifugal release collar 64 are held in position by means of a light circular tension spring 71 seated .inV a circumferential groove 72 which extends around the edge of release collar 64.

The closed end 74 of fuse casing 51 is formed with a concentric annular indentation'75 which forms a seat for a spring mounted pivotal bearing 76 which is coaxially aligned with the pivot. bearing 66 ofring pin sleeve 57. anced4 between pivot bearings 76 and 60, a solid or weighted cylinder 77 is freely mounted. The cylinder "I7 Ahas coaxialV bore 79 extending part way therethrough, the bore having a coaxial pivot seat 8i) at the inner end thereof -to seat the pivot bearing 6l) on the end of firing pin sleeve 57 which extends thereinto. At the end of solid cylinder 77' opposite the closed end of fuse casing 51 another coaxial pivot seat 81 is provided to seat spring mounted pivotal bearing 76.

Intermediate the axis of cylinder 77 and the circum-y ference thereof, facing the closed end 74 of fuse casing 51, a bore S2 is provided, extending through cylinder 77 and parallel with the axis thereof, and retains a suitable heat sensitive primer charge S4 joined endl to end with a detonator charge 85. A friction pinY 486 embedded in the primer charge 84 extends therefrom towardl the closed end 74 of the fuse case 51 which serves as a friction surface therefor. Y

Thus, when stop pin 44 is retracted from detent bore 46, spinner spring 27 unwinds to spin rocket 10 about its axis in launching tube 11. The centrifugal force produced by spinning the rocketv causes the segmented release collar 64,' which restrains tiring pin 65, to radial- Horizontally supported, and precisely bale ly separate to release ring pin 65 which under force of-spring 66-fstrikes the'percussioncap 56 in the end ofprimer cartridge which in turn bursts and ignites the propellant charge 15 to launch rocket 10 in a spinning condition. rAs the rocket 10 proceeds over its flight trajectory, rapidly 'spinning ,around its axis, the inert mass of cylinderv 77 will 'tend to resist rotation due to insufiicient friction occurring at pivotal bearings and 76as rocketf10spins therearound.V

When rocket-10, is linally decelerated though still spinning rapidiy, either byv contact with a target, or upon missing a targehwhen the rocketgdecelerates after burnout yofthe propellant charge, cylinder 77 will tend tok move toward` springv mounted pivotal Ybearing`76 which will yield sufficiently to bringpfriction pin 86v into friction contact with the'spinning surface of` casing end 74, Sufficient heat will be generated in a very short time, which heat will be conducted through the friction pin 86 to ignite the heat sensitive primer charge 84 and thereby detonate'the'detonator charge 85 and explode the rocket warhead.,

Thus, rocket 10is exploded upon Contact with a target,`

thereby providing'a high degree of safety in thehandlin'g' ofy rockets equipped with vention.,`

It can also clearly be seen that the fuse of our inthe fuse of the present invention is relatively free of complexj mechanisms, eco-f nomical in construction, and simple in operation.

While in orderVV to 'comply with kthe statute, the linvention has 'been described Vin language more or less specific as to structural features, it is to be understoody that the invention is not limited to'A the specific features shown, but that the means and construction hereindisclosed lcomprises a preferred form of putting the invention into effect, and the invention is therefore claimed in any of itsforms or modifications within the legitimate and valid scope of the appended claims.

What is claimed is: Y Y l. In the combination which includes Va rocket body having an explosive charge and a combustion chamber containing a propellant charge, and means for spinning said rocket about the longitudinal axis` thereof prior to launching; a composite fuse comprising a percussion element positioned in said combustion chamber, aspring Y actuated firing pin aligned with said percussion element and. operable to percuss said percussion element, centrif? ugally releasable restraining means holding said firing pin in cockedrposition to percuss said percussion element when said rocketis spun to release'the same, a heat responsive detonator for said explosive chargega cylinder coaxially mounted to rotate on the spin axis of said rocket body, said cylinder being longitudinally mo'vf able along said spin axis in accordance with forces produced when `said rocket is decelerated subsequent to launching thereof, a friction member communicating with said detonator and mounted on one end of said cylinder to be rotated around said spin axis thereby,VK

a friction surface' opposite said friction member to be contacted thereby when saidy cylinder is longitudinally movedv by deceleration of said rocket, whereby said friction member is rotated around said friction surface tov generate suicient heat to detonate said detonator to explode said explosive charge.-

2. lin the combination which includes a rocket body Yhaving an explosive charge anda co-mbustion chamber containing a propellant charge, and means for spinningV said rocket about the longitudinal axis theregifp riorv to launching; a fuse comprising a percussion element positioned in said combustion chamber, a spring actuated firing pin adiacent to said percussion element and operable to percuss said percussion element to ignite said propellant, centrifugally releasable restraining means radially contacting and holding said tiring pin in readiness to percuss said percussion member and radially movable to release said tiring pin when said rocket is spun, a heat sensitive detonator for said explosive charge, a pair of opposed coaxially aligned pivo-ts coaxially mounted in said rocket body adjacent to said explosive charge, a rotatable body freely suspended between said pivots, means defining a friction surface positioned opposite one end of said rotatable body, a friction member mounted in said end of said body between the axis and the outer periphery thereof adjacent said friction surface, said friction member communicating with said detonator to conduct heat thereto, said pivot at said friction surface being elastically mounted and movable along the axis of rocket rotation under deceleration force, to bring said friction member into contact with said friction surface, the heat produced by rotation of said friction member around said friction surface being conducted to said detonator to detonate said explosive charge.

3. in the combination which includes a rocket body having a forwardly disposed explosive charge and a rearwardly disposed combustion chamber containing a propellant charge, and a spin motor for spinning said rocket about the longitudinal axis therof prior to launching; a composite fuse comprising a percussion element positioned in said combustion chamber, a spring-actuated tiring pin aligned with said percussion element and operable to percuss said percussion element to ignite said propellant, centrifugally releasable restraining means radially contacting and holding said firing pin in cocked position to percuss said percussion element and movable to release said ring pin when said rocket is spun, a heat-actuated detonator for said explosive charge, a cylindrical body mounted to freely rotate on the spin axis of said rocket body and longitudinally movable along said spin axis in accordance with deceleration of said rocket body after launching thereof, means defining a friction surface positioned adjacent one end of said body` said detonator being mounted in the end of said cylinder adjacent said friction surface, a heat-conducting friction member conductively communicating at one end thereof with said detonator, the other end thereof being movable into contact with said friction surface when said cylinder moves longitudinally along said spin axis in accordance with deceleration forces, whereby said friction surface is frictionally circumscribed by said friction member to generate and conduct suicient heat to detonate said detonator to explode said explosive charge.

4. in the combination which includes a rocket having an explosive charge and a combustion chamber containing a propellant charge, and adapted to be spun around its iongitudinal axis prior to launching; a fuse for mounting in said rocket comprising a fuse body; percussion means contained in said body for igniting said propellant charge, spring actuated means for explo-ding said percussion means to ignite said propellant, restraining means radially contacting and detaining said spring actuated means, said restraining means being freely radially movable in response to centrifugal force to release said spring actuated means to explode said percussion means when said rocket is spun, heat responsive means contained in said body to detonate said explosive charge, and heat generating means operable -by deceleration forces to activato said heat responsive means upon deceleration of said reel-:et subsequent to launching.

5. In the combination which includes a rocket having an explosive charge and a combustion chamber containing a propellant charge, and adapted to be spun around its longitudinal axis prior to launching; a fuse eax/ice comprising a fuse body for mounting in said rocket, percussion means contained in said body for igniting said propellant charge, a spring loaded tiring pin operable to explode said percussion means, centrifugally releasable means radially contacting said liring pin and holding said firing pin in readiness to explode said percussion means, said releasable means being freely radially movable out of contact with said ring pin when said rocket is spun prior to launching to permit said tiring pin to explode said percussion means, heat sensitive detonating means contained in said body to ignite said explosive charge, and friction means mounted in said body, said friction means being operable by deeleration of said rocket subsequent to launching thereof to generate and conduct suticient heat to said heat sensitive detonating means to explode the same to ignite said explosive charge. Y

6. in the combination which includes a rocket having an explosive charge and a combustion chamber containing a propellant charge, and adapted to be spun around its longitudinal axis prior to launching; a fuse comprising a fuse body for mounting in said rocket, percussion means contained in said body for igniting said propellant charge, a spring loaded tiring pin operable to explode said percussion means, centrifugally releasable means radially contacting said tiring pin and holding said tiring pin in readiness to explode said percussion means, said releasable means being freely radially movable out of contact With said firing pin when said rocket is spun prior to launching to permit said tiring pin to explode said percussion means, means detining a pair of coaxially opposed pivots in said body, an inert member supported between said pivots, a heat sensitive detonator mounted in said inert member, and friction producing means operable to generate and conduct suthcient heat to explode said detonator to ignite said explosive charge when said rocket decelerates subsequent to launching.

7. In the combination which includes a rocket having an explosive charge and a combustion chamber containing a propellant charge, and adapted to be spun around its longitudinal axis prior to launching; a fuse comprising a fuse body for mounting in said rocket, percussion means contained inv said body for igniting said propellant charge, a spring loaded firing pin operable to explode said percussion means, centrifugally releasable means radially contacting said tiring pin and holding said firing pin in readiness to explode said percussion means, said releasable means being freely radially movable out of contact With said firing pin when said rocket is spun prior to launching to permit said tiring pin to explode said percussion means, means detining a pair of coaxially opposed pivots in said body, one of said pivots being immovably mounted, the other pivot being elastically mounted for longitudinal movement by deceleration of said rocket, an inert member supported between said pivots, a heat sensitive detonator mounted in said inert member, means defining a friction surface around said elastically mounted pivot, a friction member conductively connected with said heat sensitive detonator, said friction member being movable in response to longitudinal movement of said elastically mounted pivot to contact said friction surface and generate sufficient heat to explode said heat sensitive detonator when said rocket decelerates subsequent to launching.

References Cited in the file of this patent UNITED STATES PATENTS 1,152,917 Schneider Sept. 7, 1915 2,130,720 Junghans Sept. 20, 1938 FOREIGN PATENTS 436,932 Italy June 18, 1948 

